Question

Hydrogen ion concentration in mol/L in a solution of pH = 5.4 will be :

• A. $3.98\times 10^{-6}$
• B. $3.68\times 10^{-6}$
• C. $3.88\times 10^6$
• D. $3.98\times 10^8$

Answer 1

Answer: (A)

$pH=5.4$
$\therefore \left[H^{+}\right]\approx 10^{-5.4}=10^{-6}\cdot 10^{0.6}$
Antilog of $0.6$ is $\approx 4$
$\therefore \left[H^{+}\right]\approx 4\times 10^{-6}M$